


Like sea foam around your neck

by Tomicaleto



Category: Naruto
Genre: Alternate Universe - Modern Setting, Hidan and Kakuzu's terrible father/son relationship, Kakuzu won't say he's in love, M/M, Short description of injury, mermaid au, not even graphic because I don't like that
Language: English
Status: Completed
Published: 2020-07-20
Updated: 2020-07-20
Packaged: 2021-03-05 05:20:44
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,274
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25399063
Author URL: https://archiveofourown.org/users/Tomicaleto/pseuds/Tomicaleto
Summary: Kakuzu only brought him home because he saw a business opportunity, nothing less, nothing more. The fact that the strange man was beautiful had nothing to do with it.Or that time Kakuzu took home an injured stranger he found on the beach and spend the rest of the time trying to convince himself he was not getting soft.
Relationships: Kakuzu/Senju Tobirama
Comments: 8
Kudos: 47





	Like sea foam around your neck

**Author's Note:**

> This is part of Sloaners Summerfest Bingo Event!  
> Since it's winter in Argentina, I'm adapting my prompts to winter situations (I'll put which ones I used at the end notes)
> 
> I really really really ship these two  
> I can't explain why  
> This ship just sparks joy for me

Kakuzu had found the man lying unconscious on the seashore. He had been walking around, waiting for a client and his payment. The wind was punishing against his thick coat but he mostly ignored it. 

The man had a horrible gash on his side and even in his sleep he had a pained expression. He was terribly pale and completely naked. Probably near death as well. He shook his head and kept going, leaving the man behind. His client was late and his mood was quickly darkening. 

Kakuzu closed his eyes and let out a long breath, watching the small fog that formed in front of him with narrowed eyes. And then he heard a quiet moan behind him. Turning on his heels, he saw as the odd man started moving. 

Uh. 

So he wasn’t as close to death as he had thought. He considered his options. His client was obviously not going to show up, which meant he had lost a great deal and quite a lot of money. He was going to go back to his place empty handed and his son would complain again about something ridiculous or about someone telling him his stupid religion was only pure gossip. So his night would be ruined. The man lying on the beach was thin, not likely to be difficult to carry around and he didn’t have anything he could be identified with. 

Perhaps he could take him home. If he healed, he could ask for repayment. If he died, Hidan could use his body for his weird rituals. It could be a potentially good investment and Kakuzu was nothing if not good at earning money. 

With his half plan formed, he crouched next to the man and picked him up. His arms and legs dangled around with each step. Kakuzu took the opportunity to carefully examine the man’s face. 

It was an actually attractive face, with some kind of marks in red, framed with white locks dirtied with sand and sea foam. A stray thought wondered about the colour of his eyes, but he banished it as soon as it registered in his mind. He was, after all, too old to care for such foolish things like romantic pursues. And even if he wasn’t, they were usually only a waste of money. 

Soon, he was arriving home, wiping his feet before gently kicking the door open and entering. The lights were off, which meant Hidan wasn’t back yet, but the remains of the old fire had kept the place warm enough for him to first take care of the man. 

He laid him on the couch, kneeling on the floor and inspecting the wound for the first time. It looked like some kind of bite, probably by an animal. It was deep and it was at risk of being infected, so he began with that. 

He went to the bathroom and quickly grabbed a medic kit, essential when living with someone like his son, and went back to his living room. The man hadn’t moved at all in those short minutes but his blood was slowly seeping into his couch. That would be a pain to clean later. 

After cleaning, stitching and bandaging the wound, he finally decided to start a new fire. A chill had been slowly settling in the house and Hidan hated feeling cold. Once he was satisfied with the cracking fire, he raised again and went into the kitchen. 

A drink was needed. 

And just when he was about to take a sip of the whiskey he had poured himself, he heard the door open with a loud sound. Hidan was home. He waited for a couple of seconds. 

“What the fuck is this, old man?!” 

There it was. 

Soon, Hidan was entering the kitchen, his fur coat still on. “There is a naked man on the couch! Keep your disgusting sexual encounters in your room, dad! I can’t believe you!” 

He resisted the urge to roll his eyes.

“He’s not my lover, Hidan.” The boy was about to begin ranting again when his words registered in his brain. “I found him on the beach, mostly dead.” 

“It’s not like you to take on a charity case.” 

“No, it’s not. I’m waiting to see what happens.” He answered in a deadpan tone. 

“Uh?” 

“If he dies, you can keep his body, I don’t care.” He saw the moment his son’s eyes started to sparkle with excitement. “But if he lives, I can ask him to pay me back, preferably with some kind of money.” 

“Ugh, you and your love for money, this is probably why mom left you.” 

“I left your mother.” 

Hidan let out an ugly, exasperated noise and walked away, Kakuzu heard him going upstairs and slamming his door closed. And then a soft noise in the living room. It seemed Hidan had managed to wake their guest up. He sighed, left his whiskey on the counter and went to check the mysterious man’s state. 

He had woken up and was trying to sit, his hand pressing down on his bandages with a grimace on his face. Kakuzu watched him struggle for a couple of seconds before deciding to make his presence known. He didn’t want the man to tear his stitches open and waste bandages fixing it again. 

“Stop moving and lay back down.” He said, getting closer. The stranger stiffened up, turning his head to glare at him, baring his teeth. They were weirdly pointed but what caught Kakuzu’s attention was the eyes, an eerily red, exaggerated by their narrowness. 

The man hissed at him when he got closer, but he ignored him, putting a hand on his chest and forcing him to get down back on the sofa. “You’re gonna open your wound again, and I’m not gonna help you if it starts bleeding.” 

“Where am I?” His voice was deep and cold, almost unfeeling. “Who are you?” 

Kakuzu didn’t answer, leaning down and carefully pressing on the bandages to see if everything was still on its place. The man hissed again somewhere above him and a surprisingly soft hand grabbed him by his hair. 

The man’s breath hitched. “What are you doing?” His voice broke on the last word and that made Kakuzu look up. The man was staring at him, his pale cheeks covered by a light pink, his hand still entangled on Kakuzu’s hair. He realized the extremely intimate position they had ended in, with Kakuzu kneeling between the stranger legs. 

Clearing his throat, he stood up and put some distance between them. “I had to stitch you up, before you bled all over my couch. If you keep moving around, they will reopen and it will be a waste of money.” The man looked down and put his hand on the bandages, almost caressing them. Kakuzu swallowed and went back to the kitchen, with his earlier thoughts about the man’s attractiveness coming back with full force. 

He quickly drained his whiskey glass and filled up a new one, going back to the living room. The man was still rubbing the bandages, slowly back and forth, while staring at the ceiling. He looked up when he heard Kakuzu approaching him and took the glass when he offered it, taking a sip and grimacing again. 

“Not to your liking, eh? No matter, it’ll warm you up.” He watched as the man drank it completely, making a disgusted face when he finished it. “What’s your name?”  
The man stared at him in silence before sighing and cringing, his hand back on his wound. 

“My name is Tobirama Senju.” 

“Well, Tobirama Senju, my name is Kakuzu. You are in my house, after I found you half dead on the beach nearby.” Tobirama seemed unimpressed with his answer. “I brought you here and healed you, maybe you should start thinking how you’re going to pay me back for my services.” And before he could answer, he stood up and went upstairs. 

He could hear Hidan praying inside his room. Rolling his eyes, he went to his closet and started searching for clothes. He couldn’t have Tobirama roaming around naked, now that he was awake. Setting a pair of pants and a loose shirt, he walked up to his window and stared at the waves for a couple of minutes. 

\---

Days later, Tobirama started to get restless. Soon, he was walking slowly around the ground floor of the house, sometimes helping with the kitchen, sometimes just standing next to the fire, soaking in the heat, lost in his thoughts. 

He barely talked, and only with Kakuzu, when he did. Hidan only got glares and hisses. As he got physically better, Hidan’s interest in a potential sacrifice lowered as well. The boy started spending more time outside the house, arriving late at night or sometimes staying at some friend or another’s place through it. 

Such was the case of that night. Kakuzu cooked dinner for two instead of three, and had a quiet evening with Tobirama, both sitting by the fire. 

“We should check your stitches.” Tobirama looked up from the fire. “See if you’re healing correctly.” 

Kakuzu stood up and moved in front of Tobirama, one of his hands pulling on the shirt he had on, prompting Tobirama to clumsily take it off. Then he kneeled and slowly took off the bandages. His breathing hit Tobirama’s stomach faintly, making the muscles there tense and quiver in a shiver. The stitches had successfully closed the wound, a faint pink scar taking form. Kakuzu rubbed it softly, causing more shivers. Nodding to himself, he retreated. 

“It’s progressing steadily, I don’t think you’ll need more bandages. How did you end up like that, anyways? I’ve been wondering.” 

Tobirama tensed up, his lips tightly pressed together. His eyes took a calculating glint before he decided to speak. 

“I was hunting seals and got attacked.”

“You were hunting.” 

“Yes, I’m an excellent hunter.” He insisted, looking offended at the idea that Kakuzu thought differently. 

“Right, you were hunting for seals.” 

“I like how they taste.” Was the answer. Kakuzu filled that information in his mind, considering buying some to spoil Tobirama one of these nights. Then he remembered the price of seal meat in the market and abandoned the plan. Spoiling a pretty man was surely a waste of money, especially if said man had a life debt to him still unpaid. 

“Do you usually make a habit of hunting naked at the sea during winter?” Tobirama hesitated before answering. Kakuzu could almost see him think what to say to that. 

“I usually can deal with cold waters. My… house is warm enough when I get back and seal skin usually works great as a quilt.” He paused for a second. “Although this is nice too.” He added, looking at the fire. “Too bad you don’t let it burn through the night.” 

“Are you cold during your sleep?” 

“As I told you, I can endure the cold, don’t worry about it.” 

The conversation died out after that, with Kakuzu leaving for the night. The next morning, he made sure the fire was big enough to last for a couple of hours and left. He had some errands to run and it was time for him to see if there were new commissions waiting for him. Tobirama had picked up a book from their neglected library and had been avidly reading it when he had left. 

\--- 

The market was not far from the beach and its noisy environment soon embraced Kakuzu. Full of people, even with the cold weather, making him tug down his scarf, so he could breathe a little bit better.

He went through his errands quickly and efficiently, buying just what was essential and nothing more. Calculating losses and bargains as easily as breathing. Once done, he continued to a less visited and more shady part of town. 

The little office was quiet when he entered it. On top of a desk was one of his last payments for a job well done. He quickly picked it up, checking if there was something else around. No new jobs were waiting for him and he avoided thinking about how that would give him more time to spend with his new guest. Feeding Tobirama was, after all, a waste of money on extra food. 

The client that had left him waiting the day he had found Tobirama had not contacted him since, another waste of money. Luckily, the earnings he’d just collected were all in order, even with an extra amount as a tip. With his pockets full of money once again, he left the place and began his way back to his house. 

He was about to leave the market when he saw it. What looked like some kind of fur-made clothing being sold. His mind provided him with the memory of Tobirama telling him about using seal furs as quilts to keep warm. 

He had promised himself he wouldn’t spoil Tobirama, that nothing would come out of doing so except a loss of money. 

He could always ask Tobirama to pay him back. 

\---

Tobirama was asleep when he arrived, the book still on his lap. Kakuzu started putting everything in its place, before going to his room, where he hid the money earned that day. He turned around and sat on the bed, staring at the fur laid out next to him. 

Slightly annoyed with himself, he took it with him downstairs, where Tobirama was waking up, roused from his sleep by the noise of Kakuzu tidying up. His eyes got hooked to the fur on Kakuzu’s arm. 

“I’ve got you something.” Was Kakuzu's only explanation. 

Tobirama took it and checked it out. And then rubbed it on his face. 

“It’s very soft, thank you.” Kakuzu shrugged and went to the kitchen, eager to fix himself a drink before doing something stupid. When he returned to the living room, Tobirama had made himself comfortable, the fur settled around his neck, The comment about making Tobirama pay for it died in his lips. 

Tobirama looked really good, almost regal. 

They stayed the rest of the evening in a comfortable silence, just enjoying each other’s presence. 

\---

A week more passed before Kakuzu deemed Tobirama good enough to move around freely. The wound had completely healed by then and Tobirama spent most days staring out of the window, his new fur around his neck, watching the waves. 

Hidan had also returned, interrupting every free moment Kakuzu had with Tobirama just to mess with them. But he denied it when confronted about it by Kakuzu and got outright angry and offended when Tobirama suggested he was acting like a possessive little kid, afraid of his father caring more for someone else. 

That week, a new commission was thrown into Kakuzu’s path. Making both Hidan and Tobirama promise to behave, he left the house. The job took longer than he had expected, and he considered asking for more money. He would negotiate with his client when the time to pay came. 

When he returned home, he found the fire dead and the place empty. He frowned. Hidan had probably left soon after him, incapable of staying with Tobirama for long periods of time. But where was Tobirama? He should be there. 

A thought occurred to him. Perhaps Tobirama, finally strong enough to leave, had seen his chance to escape without paying his debt. He frowned, his hands curling into fists. He knew he shouldn’t feel betrayed, only angry about another waste of money, but the betrayal was there nonetheless. 

Trying to suppress his feelings, he started a new fire. He stood there for hours, his eyes drying up. Night quickly fell outside the house, Kakuzu finally moving from the fireplace to make himself some food. 

He heard the door open and soft feet paddling around the place. Not Hidan. The steps got closer and a sudden weight dropped onto his back. He looked over his shoulder, finding a tuft of white hair. Tobirama. 

“I’ve got you something.” Said the man. Kakuzu put down the utensils he was holding, turning around. Tobirama took the opportunity to rub his cheek against Kakuzu’s chest, the same way he had done it when given the fur. 

He took one of his hands, dropping something in it. Kakuzu looked down, finding three black pearls. 

“You kept talking about paying you back, but I don’t really have money like you humans do.” He said, with a smirk. “But I do know how worthy these seem to be for all of you. Sailors talk about their beauty all the time, they’re really annoying.” 

“Us humans?” 

Tobirama didn’t answer, he’d gone back to rub himself against Kakuzu. He clenched the pearls in his fist. 

“I thought you had left.” 

“I did, I had to find something to pay my debt fast. It’s not good for a courtship to start with one of the members owing something to their potential partner. I don’t want my brother nagging me about it after we marry. Not after all my complaining about his chosen husband.” 

Kakuzu was too stunned to answer. 

“But that’s over now, we can proceed with our planning.” Tobirama continued, dragging him towards the couch, forcing him to sit and cuddling to his side, the fur tickling his cheek. “Obviously, you won’t be able to live in my cove, I don’t think humans can stand such low temperatures. And your offspring can’t be left behind, no matter how bothersome he is.” 

Kakuzu let out a humming sound. Tobirama stopped and looked directly at him. 

“Your cove?” 

“Yes, I decorated it myself. I won’t mind staying here most of the year, as long as you are aware that I will visit the place.” 

Kakuzu frowned, still trying to catch up with the situation. Being straightforward seemed the best strategy to understand. 

“What exactly are you talking about?” 

“A cove is the place where most merpeople build their homes. It allows us to collect treasures and food, it protects us from the cold during winter and keeps us cool enough during summer.” 

“You’re a mermaid.” He said, disbelieving. 

“You… didn’t know that?” Tobirama looked confused for a second. “I was not exactly hiding it. I thought you had realized when you saved me on the beach.”

Kakuzu didn’t say anything. He thought imprudent clarifying he had only seen a business opportunity then. Perhaps he should have been more surprised, but he had lived with Hidan and his strange religion for years now. Mermaids seemed rather tame compared to what he had found Hidan doing in some of his rituals. Especially handsome mermaids like Tobirama, who looked good with soft fur around his neck. Tobirama who had apparently decided to plan their whole future wedding. 

Wait. He had something to say about that. 

“We cannot have a big celebration, weddings are expensive.” 

Tobirama nodded in agreement. “You’re right, maybe we should elope once the period of courtship is complete.” He put his finger on his lip, deep in thoughts. “Yes, that would be ideal, that way I could avoid introducing you to my brother, he can be quite overwhelming.” 

They kept planning their future together for hours, the dinner preparation long forgotten. Hidan arrived a couple of hours after Tobirama decided to move onto Kakuzu’s lap, making a scandalized noise which only got worse when Tobirama told him he was going to marry his dad. 

Life would be getting a lot noisier but Kakuzu would not really care as long as money was abundant and Tobirama and Hidan didn’t kill each other in the end.

**Author's Note:**

> Tobirama: *receives a gift* we should get married  
> Kakuzu: nothing too expensive  
> Tobirama: valid
> 
> I've been wanting to write a mermaid au for this ship for a while and let me tell you, these two are not easy to write.  
> Also, Tobirama giving Kakuzu pearls so he can sell them because he noticed how fond of money Kakuzu is? Who said romance is dead, am I right? 
> 
> The prompts were: Secret mermaid and Injured on the beach  
> I was not picturing any beach in particular this time, just had a vague idea of a very foggy and cold place during winter.  
> (You can find me on tumblr! come and talk to me!)


End file.
